Plasma treatment of an elastomeric material for adhesion

ABSTRACT

Elastomeric components, such as a shoe outsole, are treated with a plasma application to clean and activate the elastomeric component. The application of plasma is controlled to achieve a sufficient surface composition change to enhance adhesion characteristics while not adversely physically deforming the elastomeric component. The plasma treatment is applied to increase carbonyl functional group concentrations within an altered region of the elastomeric component to within at least a range of 2%-15% of carbon atomic percentage composition. The cleaning and activation is controlled, in part, by ensuring a defined height offset range is maintained between the elastomeric component and the plasma source by a generated tool path. The elastomeric component may then be adhered, with an adhesive, to another component.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/842,564, filed Sep. 1, 2015, now U.S. Pat. No. 9,941,099 and entitled“PLASMA TREATMENT OF AN ELASTOMERIC MATERIAL FOR ADHESION,” which claimspriority to U.S. Provisional Application No. 62/044,769, filed Sep. 2,2014, and entitled “PLASMA TREATMENT OF AN ELASTOMERIC MATERIAL FORADHESION.” The entirety of both of the aforementioned applications isincorporated by reference herein.

TECHNICAL FIELD

Aspects provide methods and systems for cleaning and/or priming asurface for adhesion by an adhesive.

BACKGROUND

Prior to adhering an elastomeric component, such as a component madefrom saturated or unsaturated rubber(s), a surface cleaning istraditionally performed. The surface cleaning may include bothmechanical cleaning to remove particles as well as chemical cleaning toremove oils and other agents that could affect an adhesive bond. Thismulti-step cleaning process has been used traditionally in the footwearindustry to prepare and prime an outsole component for eventual bondingwith an upper and/or midsole portion. However, this cleaning process canconsume energy (e.g., drying energy), chemicals, (e.g., solvents), andtime.

BRIEF SUMMARY

Aspects hereof provide systems and methods for cleaning an elastomericcomponent with plasma. The component is identified such that a plasmasource may be positioned relative thereto. The positioning of the plasmasource is within a height offset range of 20-40 millimeters of thecomponent to achieve a desired surface treatment without thermallydamaging the component. Plasma is applied in one or more applications tothe component to sufficiently clean and activate the component surface,such as by applying plasma until the elastomeric component has acarbonyl functional group concentration of 2% to 15% within an alteredregion of the component. Following the achievement of the appropriatecarbonyl functional group concentration, an adhesive is applied to thecomponent.

This summary is provided to enlighten and not limit the scope of methodsand systems provided hereafter in complete detail.

DESCRIPTION OF THE DRAWINGS

The present invention is described in detail herein with reference tothe attached drawing figures, wherein:

FIG. 1 depicts an exemplary plasma cleaning system, in accordance withan aspect hereof;

FIG. 2 depicts an exemplary component on to which plasma is beingapplied along a tool path, in accordance with an aspect hereof;

FIG. 3 depicts an exemplary component on to which a second applicationof plasma is being applied along a tool path, in accordance with anaspect hereof;

FIG. 4 depicts a cross-section perspective of a component having analtered region from the application of plasma, in accordance with anaspect hereof;

FIG. 5 depicts a cross-sectional perspective of a first component, anadhesive, and a second component as mated, in accordance with an aspecthereof;

FIG. 6 depicts an exemplary method for plasma cleaning a component, inaccordance with an aspect hereof; and

FIG. 7 depicts an additional exemplary method for plasma cleaning acomponent, in accordance with an aspect hereof.

DETAILED DESCRIPTION

Aspects hereof provide systems and methods for cleaning an elastomericcomponent with plasma. The component is identified such that a plasmasource may be positioned relative thereto. The positioning of the plasmasource is within a height offset range of 20-40 millimeters of thecomponent to achieve a desired surface treatment without thermallydamaging the component. Plasma is applied in one or more applications tothe component to sufficient clean and activate the component surface,such as by applying plasma until the elastomeric component has acarbonyl functional group concentration of 2% to 15% of carbon atomicpercentage within an altered region of the component. Following theachievement of the appropriate carbonyl functional group concentration,an adhesive is applied to the component.

As will be discussed throughout, it is contemplated that aspect providedherein are directed to the manufacture of at least portions of anarticle of footwear. As such, an article of footwear, such as a shoe,will be discussed for contextual purposes, but it is not limiting as tothe scope of applicability for aspects claimed herein. While thefollowing examples of shoe uppers and shoe bottom units are presented ina simplified fashion for exemplary purposes herein, in practice a shoeupper may comprise a large number of individual parts, often formed fromdifferent types of materials. Alternatively, a shoe upper may beprimarily formed from a single manufacturing technique, such as weavingor knitting, to concurrently and integrally form two or more portions ofthe shoe upper. The components of a shoe upper may be joined togetherusing a variety of adhesives, stitches, and other types ofjoining/bonding components.

A shoe bottom unit may often comprise a shoe sole assembly with multiplecomponents. For example, a shoe bottom unit may comprise an outsole madeof a relatively hard and durable material, such as an elastomericmaterial like a saturated or an unsaturated rubber, which contacts theground, floor, or other surface. A shoe bottom unit may further comprisea midsole formed from a material that provides cushioning andabsorbs/attenuates force during normal wear and/or athletic training orperformance. Examples of materials often used in midsoles are, forexample, ethylene vinyl acetate (“EVA”) foams, polyurethane foams, andthe like. Shoe soles may further have additional components, such asadditional cushioning components (such as springs, air bags, and thelike), functional components (such as motion control elements to addresspronation or supination), protective elements (such as resilient platesto prevent damage to the foot from hazards on the floor or ground), andthe like. While these and other components that may be present in a shoeupper and/or a shoe bottom unit are not specifically described inexamples herein, such components may be present in articles of footwearmanufactured using systems and methods in accordance with aspectshereof.

As can be appreciated by the following, it is contemplated that plasmacleaning and features discussed in association may be used for thecleaning of any material or component. For example, it is contemplatedthat aspects provided herein may be utilized to prepare and clean aplastic surface (e.g., a polymer-based material) for the adhesion of oneor more elements. To this example, it is contemplated that an outsoleplate or other sole structure may be treated with plasma in preparationfor application of a traction element, such as a cleat. In an exemplaryaspect, plasma cleaning is applied to at least a surface of a rubberoutsole to allow for an effective bond with a midsole portion. It iscontemplated that the plasma cleaning is used in the alternative of atraditional chemical solvent to degrease the outsole surface for receiptof an adhesive. Further, the chemical alteration of the elastomericcomponent's surface by the plasma may reduce or eliminate the typicalapplication of a primer that is traditionally used for increased bondingof an adhesive. Therefore, use of plasma may reduce the environmentaleffects of chemical applications for cleaning and/or priming.

Further, as will be evident hereinafter, the use of plasma as a cleaningmechanism has been contemplated in other applications for use on othermaterials previously. For example, the computing industry hasimplemented the use of plasma for cleaning the surface of silicon chips.Unlike the elastomeric components contemplated herein, the silicon chipis able to withstand a higher intensity of plasma that is delivered froma closer distance than contemplated herein. If the same plasma intensityand distance as used in the silicon chip industry was applied to anelastomeric component, such as a rubber outsole, the elastomericcomponent may be damaged, such as deformed or even burnt. Further, thechemical composition of the elastomeric components differs from thesilicon chip industry target components such that a different resultingeffect is realized from the application of plasma energy. For example, arubber component that is exposed to plasma at given heights of exposuregenerates functional groups (e.g., carbonyl groups) that are effectivefor adhesion purposes. Additionally, as will be discussed hereinafter,the elastomeric material provided herein may benefit from amultiple-pass application approach for plasma to ensure that anappropriate surface temperature is not exceeded for the elastomericcomponent while still providing an opportunity for the plasma tochemically alter the elastomeric component surface for adhesionpurposes. In the computing chip industry, a single plasma application ata slower speed, higher intensity, and/or closer offset distance may beimplemented as a concern of thermal damage to the substrate of thesilicon chip is less.

Referring now to FIG. 1, an exemplary plasma cleaning system 100 for usewith an elastomeric component is depicted, in accordance with aspectshereof. The components are depicted generically for discussion purposes.It is understood that one or more of the components may be omitted,moved, or repositioned/reconfigured in aspects hereof. Further, it iscontemplated that additional components (e.g., conveyance mechanisms,plasma sources, adhesive applicator, etc.) may be implemented. Further,while an illustrative configuration of the various components aredepicted, it is understood they are exemplary in nature and are notlimiting. For example, a conveyance mechanism 104 is illustrated as abelt-like mechanism; however, it is contemplated that a component may bemoved/conveyed by any means, such as a multi-axis robot or a human.Similarly, a plasma torch 116 is depicted as being coupled with amulti-axis mechanism 114; however, it is contemplated that any movementmechanism may be implemented to achieve appropriate dimensional movement(e.g., axial movement and rotation).

The system 100 is comprised of a component 102, the conveyance mechanism104, a conveyance drive 106, a vision system/camera 108, a field-of-view110, a computing device 112, the multi-axis mechanism 114, the plasmatorch 116, a multi-axis mechanism 118, and an adhesive applicator 120.It is understood that any combination of components, may be used in anynumber and in any fashion within aspects hereof.

Plasma is an ionized gas and is one of the four fundamental states ofmatter. Plasma is a gas (e.g., multiple element gas and single elementgas) into which sufficient energy is provided to free electrons fromatoms or molecules and to allow both species, ions and electrons, tocoexist. Stated differently, plasma is an ionized gas consisting ofpositive ions and free electrons in proportions resulting in more orless no overall electric charge. Plasma may exist in both a thermal anda non-thermal form. The distinction between thermal and non-thermal maybe determined by the temperature of electrons, ions and neutrals.Thermal plasmas have electrons and the heavy particles at substantiallythe same temperature, i.e., they are in thermal equilibrium with eachother. Non-thermal plasmas have the ions and neutrals at a much lowertemperature whereas electrons are at a significantly greatertemperature. Aspects provided herein rely on a non-thermal plasma forplasma cleaning of an elastomeric component, in accordance with anexemplary aspect.

The component 102 is depicted in a generic manner for illustrationpurposes. However, as already discussed, it is contemplated that thecomponent 102 may be a portion of an article of footwear, such as a shoeoutsole. Any component formed from any material is contemplated, such aspolymer-based materials. In exemplary aspects, an elastomeric component,which is a component formed from an elastomeric material, is treated bythe methods and systems provided herein. Elastomeric materials includepolymeric compounds having viscoelasticity. Examples of elastomericmaterials include both saturated rubbers and unsaturated rubbers. Anunsaturated rubber is an elastomeric material that can be cured withsulfur vulcanization, such as natural rubber, isoprene rubber, butadienerubber, chloroprene rubber, polychloroprene, butyl rubber,styrene-butadiene rubber, and the like, for example. A saturated rubberis a rubber that cannot be cured with sulfur vulcanization. Examples ofsaturated rubber include ethylene propylene rubber, ethylene propylenediene rubber, silicone rubber, polyacrylic rubber, ethylene-vinylacetate (EVA), and the like, for example.

The component 102 may have any shape, size, and orientation. In anexemplary aspect the component 102 is a shoe outsole having theground-contacting surface (e.g., treads) oriented away from the plasmatorch 116. In the non-limiting example illustrated, the tread side wouldbe positioned on the conveyance mechanism 104; however, it iscontemplated that any (or no) conveyance mechanism may be used inaspects hereof. This presented orientation of the component 102 allowsfor plasma to be applied to a top surface of the component 102, whichcan then be primed for receipt of an adhesive for eventual bonding withanother component, such as a bottom surface of a midsole, for exampleand as will be depicted in FIG. 5 hereafter.

The conveyance mechanism 104 is depicted as a belt-like mechanism;however, it is contemplated that it may be any mechanism effective forpositioning the component 102 in a location for operations providedherein (e.g., plasma application). It is further contemplated that theconveyance mechanism 104 is adapted for receipt of plasma energy thatmay not be contained to the component 102. For example, it iscontemplated that the conveyance mechanism 104 is formed from a materialthat is tolerant to plasma energy to allow consistent and continuedoperation. The conveyance mechanism is motioned by conveyance drive 106.The conveyance drive 106 is effective for causing the conveyancemechanism 104 to position the component 102 at desired locations foroperations provided herein. As will be discussed, it is contemplatedthat the conveyance drive 106 is controlled by a computing device, suchas the computing device 112, for example.

In order to identify the size, shape, orientation, and specifics of thecomponent 102, it is contemplated that a vision system or other partidentification system (e.g., imaging, detection, sensing) isimplemented. For example, the camera 108 having a field-of-view 110 isdepicted as providing sensing information to a computing device, such asthe computing device 112. The vision system having the camera 108 iseffective for locating and identifying a component, such as thecomponent 102. The vision system may utilize a three-dimensional imagecapture technology (e.g., multiple perspective cameras, laser scanning)to generate a three-dimensional mapping of the component for thecomputing device 112 to generate tool path that can be used by one ormore components (e.g., the plasma torch 116, the multi-axis mechanism114, 118, the adhesive applicator 120), as will be discussed in greaterdetail hereinafter. Therefore, it is contemplated that the camera 108 isoperably (e.g., electrically) coupled with the computing device 112 toeffective communicate information there between.

The computing device 112 is but one example of a suitable computingenvironment and is not intended to suggest any limitation as to thescope of use or functionality of the invention. Neither should thecomputing device 112 be interpreted as having any dependency orrequirement relating to any one or combination of componentsillustrated. The computing device 112 includes a bus that directly orindirectly couples the following devices: memory, one or moreprocessors, and one or more components (e.g., multi-axis mechanisms,plasma torch, and adhesive applicator).

Computing device 112 typically includes a variety of computer-readablemedia. Computer-readable media can be any available media that can beaccessed by computing device 112 and includes both volatile andnonvolatile media, removable and non-removable media. By way of example,and not limitation, computer-readable media may comprisecomputer-storage media and communication media. Computer-storage mediaincludes volatile and nonvolatile, removable and non-removable mediaimplemented in any method or technology for storage of information suchas computer-readable instructions, data structures, program modules orother data.

Computer-storage media includes RAM, ROM, EEPROM, flash memory or othermemory technology, CD-ROM, digital versatile disks (DVD) or otheroptical disk storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices. Computer storage media doesnot comprise a propagated data signal.

Communication media typically embodies computer-readable instructions,data structures, program modules or other data in a modulated datasignal such as a carrier wave or other transport mechanism and includesany information delivery media. The term “modulated data signal” means asignal that has one or more of its characteristics set or changed insuch a manner as to encode information in the signal. By way of example,and not limitation, communication media includes wired media such as awired network or direct-wired connection, and wireless media such asacoustic, RF, infrared and other wireless media. Combinations of any ofthe above should also be included within the scope of computer-readablemedia.

Memory includes computer-storage media in the form of volatile and/ornonvolatile memory. The memory may be removable, nonremovable, or acombination thereof. Exemplary memory includes non-transitory,solid-state memory, hard drives, optical-disc drives, etc. Computingdevice 112 includes one or more processors that read data from variousentities.

The computing device 112 is therefore effective for coordinating one ormore components provided herein for purposes of accomplishing methodssupported herein. For example, it is contemplated that the computingdevice 112 processes instructions allowing for an image captured by thecamera 108 to identify and position the component 102 in order togenerate a three-dimensional mapping of the component 102. Thisthree-dimensional mapping of the component 102 may then be used by thecomputing device 112 to generate one or more tool paths for one or morecomponents. For example, a tool path for the application of plasma maybe generated by the computing device 112, which will be implemented bythe multi-axis mechanism 1145 and the plasma torch 116. Similarly, it iscontemplated that a tool path may be generated by the computing device112 for use by the multi-axis mechanism 118 and/or the adhesiveapplicator 120 for the application of adhesive to the component 102. Atool path is a component-specific coordination of movement in space fora given mechanism/tool that accounts for specific (e.g., size, shape,location, orientation) of a component. As provided herein, it iscontemplated that any number of components may be used in combination toachieve the results intended. For example, it is contemplated that one,two, three . . . or ‘N’ number (where ‘N’ is any number) of multi-axismovement mechanisms, plasma torches, and/or adhesive applicators can beused in any combination. Further, while examples herein provide for acombination of components, such as a movement mechanism, plasma torch,and adhesive applicator, it is understood that one or more of thosecomponents may be omitted altogether, combined into a common physicaldevice, and/or modified. Examples include a plasma torch only, anadhesive applicator only, a plasma torch and movement mechanism only, anadhesive applicator and movement mechanism only, a plasma torch andadhesive applicator only, for example.

While a single computing device 112 is depicted, it is contemplated thatany number of computing device in any configuration may be implementedto achieve aspects provided herein.

The multi-axis mechanism 114, 118 is generally depicted as a multi-axialmovement mechanism that has multiple degrees of movement freedom (e.g.,X, Y, Z, rotation about each axis). However, as previously discussed,the various components of FIG. 1 are depicted for exemplary purposes andare not intended to be limiting. For example, it is contemplated thatone or more of the movement mechanisms may be X-Y tables or othermovement mechanisms effective for achieving a degree of motion forgenerating results provided herein (e.g., application of plasma,application of adhesive).

The multi-axis mechanism 114, 118 is coupled with a computing device,such as the computing device 112. The computing device may be effectivefor the control of movement of the multi-axis mechanism 114, 118, suchas through computer-numeric-control (CNC) movement control, for example.Further, it is contemplated that the computing device is effective forcoordinating the movement and application of various components (e.g.,the multi-axis mechanism 114 and the plasma torch 116). Further, whilethe computing device 112 is depicted as being physically independent ofthe multi-axis mechanism 114, it is contemplated that any configuration(e.g., integrated) may be utilized.

The plasma torch 116 is effective for applying plasma to a component102. In an exemplary aspect, the plasma torch is a plasma generator thatutilized a multi-gas composition (e.g., atmospheric air) to form theplasma. For example, it is contemplated that the application of plasmato the component occurs at atmospheric pressure, which allows for acontinuous processing (rather than batch processing). Plasma generatedat atmospheric conditions is referred to as atmospheric pressure plasma.The plasma torch generates plasma by a high voltage between an anode andcathode, which is blown out through a nozzle on the plasma torch 116with a working gas, such as atmospheric air. The frequency of energy anda pulsing pattern (e.g., single pulse of energy, double pulse of energy)of the energy may be varied to form the plasma, in some aspects. It iscontemplated that a rotary nozzle may be implemented to apply plasma ina pulse-like manner to limit the heat input to the component 102, whichcould deform or otherwise negatively affect an elastomeric material. Tofurther limit the effect of thermal input, it is contemplated that amulti-pass tool path may be implemented that uses multiple plasmasources or a repeated passing of a common plasma source, in an exemplaryaspect. The nozzle and/or the number of plasma application passes may beadjusted to achieve a desired surface treatment (e.g., cleaning,activation) while maintaining a temperature below a predefined value, inan exemplary aspect.

The application of plasma to an elastomeric component results in aphysical cleaning as well as an activation of the elastomeric material.As such, variables associated with the application of plasma affect thecleaning and activation of the material. Therefore, testing hasdetermined that suitable results are achieved with specific variableranges. For example, when a plasma torch is placed outside of a 20-40millimeter (mm) offset height from the surface of the component 102 adesired surface treatment may not be achieved. In particular, a rubbercomponent to which adhesive is to be applied for an article of footwearmay not achieve a desired level of carbonyl functional group developmenton a treated surface when the plasma torch is positioned outside of a20-40 mm offset height range. A 25-35 mm offset height is used in anaspect. A 35-40 mm offset height is used in an aspect. Application ofplasma outside of the provided ranges may result in an insufficientsurface treatment to a particular material. However, it is contemplatedthat different materials may achieve a desired surface treatment outsideof provided ranges. Further, it is contemplated that travel speeds andplasma intensities may be adjusted to achieve provided ranges. Further,while a usable surface treatment (e.g., activation and/or cleaning) maybe achieved at a closer distance than provided by the ranges, an inputheat value of the plasma may exceed a predefined value that could resultin surface deformation, burning, or other undesired results, in anexemplary aspect.

In an exemplary aspect, the application of plasma is provided to formfunctional carbonyl (i.e. C═O) groups on the surface of the component102. Carbonyl groups may result from a formation of a radical state onthe surface of the component 102 caused by the application of plasma tothe surface. The radical state of the surface reacts with oxygen, suchas oxygen found in the ambient air or from the working gas of theplasma, to form the functional carbonyl groups. The formation of thecarbonyl groups may be affected by the working gas (e.g., atmosphericair that is a mixed gas, oxygen (e.g., 02) gas, hydrogen (e.g., H2)gas), the travel speed, the offset height, the material of thecomponent, the duration of application, the pattern of application, andthe like. In an aspect, a 2% to 15% carbonyl functional group formationon the component surface (i.e. altered region) composition is achieved.Within this range, a sufficient adhesion bond can be achieved for use inan article of footwear, for example. In an aspect, a 2%-9% formation ofcarbonyl as a surface composition is achieved. Stated differently, asurface composition in an altered region of the component increases incarbonyl functional groups by at least 2% as a result of one or moreplasma applications to the surface of the component. As will bediscussed with FIG. 4, a surface composition is in reference to analtered region that extends at least a certain distance (e.g.,penetration depth) into the component. For example, aspects achieve apenetration depth of the 10-800 nanometers in which a carbonylfunctional group is sufficiently detected. Therefore, at least a 2%increase in carbonyl functional groups is achieved in an altered regionof the component surface extending inwardly 10-800 nanometers, in anexemplary aspect.

In addition to an increase in carbonyl functional groups within thealtered region, aspects contemplate applying plasma to achieve areduction in the carbon to carbon (C—C) and the carbon to hydrogen (C—H)bonds within the altered region. In an aspect, a 27%-17% reduction inC—C and C—H bonds is achieved, which further aids in the adhesioncharacteristics of a to-be-applied adhesive. Variations in C—C and C—Hbonds are affected by plasma application variable discussed above (e.g.,offset height, power, speed, and number of passes, material, and thelike). The listing of percentages of carbon based groups (e.g., C═O,C—C, C—H) is a carbon atomic percentage as used herein.

The following table provides data on the composition percentage forcarbon found in an altered region of a rubber plasma cleaned component.The percentage of carbonyl functional group in the control samplesregistered at 0.3% and 0.4%. However, following a plasma treatment at 30mm, a first test resulted in a 9.1% and a second test resulted in an8.3% atomic composition percentage. Therefore, the application of plasmaat 30 mm increased the carbonyl composition 8.8% (9.1−0.3) to 7.9%(8.3−0.4), in this exemplary data. This increase in carbonyl functionalgroups in the 7.9% to the 8.8% range allows for the plasma cleanedcomponent to achieve a desired adhesion characteristic. Similarly, theC—C bonds and the C—H bonds decreased as a result of the plasma cleaningat 30 mm from a 94.2% and 94.5% down to a 67.3% and 70.1%, whichprovides a C—C and C—H bond composition decrease in the range of 27.2%and 24.1%. In aspects, it is contemplated that achieving a carbonylconcentration percentage in the 2% to 15% range allows for anelastomeric component to have sufficient adhesion characteristics for anarticle of footwear.

C═O C—O & C—N C—C & C—H   30 mm test 1 9.1% 23.6% 67.3%   30 mm test 28.3% 21.6% 70.1% 37.5 mm test 1 3.7% 22.9% 73.4% 37.5 mm test 2   3%19.7% 77.4%   45 mm test 1 1.9% 10.9% 87.2%   45 mm test 2 1.8% 10.5%87.7% Control 1 0.3% 5.6% 94.2% Control 2 0.4% 5.2% 94.5%

The foregoing is exemplary in nature and is constrained to an exemplaryplasma torch configuration on an exemplary elastomeric rubber componentand is not limiting in scope, but exemplary in nature.

While a single plasma torch 116 is depicted in FIG. 1, it iscontemplated that multiple plasma torches may be implemented to achievedaspects hereof. Further, it is contemplated that a common plasma torchmay operate on a multi-pass tool path that re-applies plasma to one ormore portions of the component. The use of multiple plasma torches orthe re-application of plasma by a common plasma source may allow for apredefined delay time to be experienced by a component, which may beeffective for the surface of the component to remain below a predefinedtemperature. Remaining below a temperature may limit surface deformationthat is unintended or undesirable.

Returning to FIG. 1, the adhesive applicator 120 is an applicator ofadhesive. As the adhesive applicator 120 is coupled with the multi-axismechanism 118, a computing device can control the application ofadhesive over a three-dimensional space. It is contemplated that theadhesive applicator 120 is a spray applicator, a brush applicator, aroller applicator, and/or the like. In an exemplary aspect, adhesive isapplied to the component after the application of plasma, which cleansand activates (e.g., increases carbonyl functional groups) the surfacefor receipt of the adhesive.

While a specific arrangement of devices and components are depicted inFIG. 1, it is understood that aspects contemplated herein are notlimited to the illustrations and discussion of FIG. 1. For example, itis contemplated that different conveyance mechanisms, differentmulti-axis mechanisms, and the like may be implemented. Further, it iscontemplated that a different number and configuration of mechanisms andcomponent s may be implemented. For example, two or more plasma torchesmay be utilized in exemplary aspects.

FIG. 2 depicts plasma cleaning 200 of an exemplary elastomeric component202, in accordance with aspects hereof. In this example, a superiorsurface 212 (e.g., non-treaded surface) of a shoe outsole representingthe component 202 is depicted. A plasma torch 204 is generally depictedas having multiple degrees of freedom for traversing the component 202.Plasma 206 is depicted as emanating from the plasma torch 204 on to thesurface 212. An exemplary tool path 208, which may be preprogrammed ordynamically determined by a computing device, is illustrated fordiscussion purposes.

The tool path 208 may traverse the component 202 in any manner. In thecurrently illustrated example, a medial to lateral motion path isdepicted for purposes of achieving a throughput time while achieving asurface preparation by the plasma 206. In alternative aspects a heel totoe or a perimeter-based tool path may alternatively (or additionally)be implemented. The tool path 208 may be generated to allow applicationof plasma to areas of the surface 212 intended for application ofadhesive, if not the entirety, in an exemplary aspect. Further, while aseemingly two-dimensional tool path 208 is illustrated, it is understoodthat the component 202 may be multi-dimensional and therefore the toolpath 208 is actually in a three-dimensional space to ensure appropriateoffset heights are achieved during the application of plasma 206. Inthis example, the general direction of the plasma torch is in thedirection of arrow 214 (a toe to heel direction); however, it isunderstood that the arrow 214 may be oriented in any appropriatedirection. Further, the tool path 208 may also include informationdictating the plasma intensity, angle of application, speed of movement,and the like.

Area 210 represents a plasma cleaned (e.g., cleaned and activated withcarbonyl functional groups) area of the component 202. The area 210 hasa carbonyl functional group percentage of composition that is at least2% greater than the non-plasma treated (e.g., heel end) areas of thesurface 212.

FIG. 3 depicts and alternative plasma cleaning 300 of FIG. 2 plasmacleaning 200, in accordance with aspects hereof. In this example, theplasma torch 204 applies plasma 206 along the tool path 208 on thesurface 212 of component 202 forming a first plasma application area210. Further, a second plasma torch 304 follows a tool path, such as thetool path 208, over the surface 212 forming a second pass area 310. Thesecond pass area 310 is a second application of plasma, such as plasma306, to further clean and activate the surface 212. A second plasmaapplication may allow the thermal input of the plasma to be limited in amanner that reduces thermally-induced deformation or damage to thesurface 212. For example, the second plasma torch 304 may delay apredetermined time (which may be factored into the tool path) prior toapplying plasma 306. This introduced delay may allow the surface 212 tothermally stabilize or reduce prior to introducing thermal energy fromthe plasma in the second pass.

While a specific arrangement and configuration of tool path, components,and timing is illustrated in FIG. 3, it is exemplary in nature and notintended to be limiting in nature. For example, a second plasmaapplication pass may be provided by the plasma torch 204 that providedthe initial plasma application. Further, it is contemplated that theentire first plasma application may be applied prior to applying thesecond plasma application, in an exemplary aspect. Additional variationsare contemplated. Further, it is contemplated that additionalapplication of plasma (e.g., three or more) may be provided in aspects.Plasma application may also occur in specific regions and at variedspeeds, heights, angles, and intensities in some aspects. Further, it iscontemplated that any sequence of operations may be implemented. Forexample, a first plasma pass, a first adhesive pass, a second plasmapass, and a second adhesive pass may be performed on one or more regionsof the object. Any order of the operations may be performed.

FIG. 4 depicts a cross-sectional perspective 400 of a component 406having an altered region 408 from the application of plasma 404 from aplasma source 402, in accordance with aspects hereof. The altered region408 extends from a surface 412 inwardly to a depth 414, which may be10-800 nanometers. The altered region 408 is a region extending from thesurface 412 where the plasma has altered the composition of material toincrease carbonyl functional groups and/or reduce C—C and C—H bonds.Below the depth 414 the detectability of this composition alteration isinsubstantial, in an exemplary aspect. The altered region is depicted ashaving a depth of 418, which may range from 10-800 nanometers inexemplary aspects utilizing parameters provided herein. For example, anoffset height of 416 between the plasma source 402 nozzle and thesurface 412 results in the depth 418 for the altered region 408, in anexemplary aspect. FIG. 4 is not drawn to scale, but instead illustratedfor discussion purposes.

FIG. 5 depicts a cross-sectional perspective 500 for a component 506bonded with a component 502 by an adhesive 504, in accordance withaspects hereof. In this example, the component 506 was plasma cleaned inaccordance with aspects provided herein on a surface 508. The plasmacleaning and parameters selected for the plasma cleaning resulted in asurface treatment to surface 508 that is effective for adhesion byadhesive 504, such as an increase in carbonyl functional groups. It isunderstood that if carbonyl functional group increases in providedranges, C—C bond and C—H bond decreases outside of provided ranges, andother parameters provided herein may result in an ineffectively preparedsurface for adhesion purposes, in exemplary aspects. The elements ofFIG. 5 are not drawn to scale and illustrated for exemplary purposesonly. It is contemplated that a surface proximate the adhesive 504 ofthe component 502 may also be plasma cleaned to achieve a desiredadhesion. For example, if the component 502 is an EVA-based material(e.g., EVA midsole), plasma cleaning may enhance the adhesion of theadhesive 504 for bonding with the component 506 (e.g., a rubberoutsole), in an exemplary aspect.

FIG. 6 depicts a flow diagram 600 representing a method of cleaning anelastomeric component with plasma, in accordance with aspects hereof. Ata block 602, a position of a component is determined. For example, it iscontemplated that a visions system may be implemented to capture animage of the component. The position determination may be used fordetermining an appropriate tool path for a plasma source to traversewhile applying plasma to the component. Further, the determination ofthe position may be used for identifying the part to apply anappropriate plasma cleaning operation. Further, determining of theposition may be usable to appropriately position one or more componentsfor plasma application, such as positioning a plasma torch at anappropriate relative location to the component. An appropriate locationmay include a height offset range to achieve an appropriate surfacetreatment on the component by the plasma. The determination of theposition may be done in connection of a computing device and/or one ormore sensors (e.g., proximity sensor).

At a block 604, a plasma torch is positioned. The positioning of theplasma torch may be aided by a computing device controlling a multi-axismechanism (e.g., multiple degree of freedom robot). The positioning ofthe plasma torch may position the plasma torch at a predetermined offsetheight from the surface of the component, such as within a 20-40 mm, a25-35 mm, and/or a 35-40 mm offset height range.

At a block 606, plasma is applied to the component. The plasma torch maydirect plasma to the component along a specified three-dimensional space(e.g., a tool path) at a specified intensity and/or at a specifiedapplication rate (e.g., speed), in an exemplary aspect. The applicationof plasma to an elastomeric component generates carbonyl groups in analtered region extending into the component from the surface, asdepicted at a block 608. The generation of the carbonyl groups isdetermined, in an aspect, based on parameters associated with theapplication of the plasma and parameters of the component material. Forexample, the working gas of the plasma, the nozzle of the plasma source,the offset height of the plasma source, the speed of plasma application,the tool path, and the like all affect the formation of the carbonylgroups, which can vary dramatically based on the parameters. Further,the material, such as a rubber material, responds differently than othermaterials (e.g., metals, silicon, and the like) to the parameters ofplasma application, which cause a different functional group formationand composition. Additionally, because the surface treatment with plasmais performed, in an aspect for adhesion improvement by an adhesive, thecarbonyl group increase in the provided ranges has been found to provideeffective adhesion results, in exemplary aspects.

At a block 610, an adhesive is applied to the component. The adhesivemay be any material effective to bond the component with a desiredmating component, such as a shoe midsole. In an exemplary aspect, theadhesive is glue that is effective for bonding a rubber outsole that hasbeen plasma treated with an EVA midsole, for example. The adhesive maybe applied by an adhesive applicator and a multi-axis mechanism, whichmay be controlled, in part, by a computing device.

While specific steps are depicted in an exemplary order with FIG. 6, itis understood that additional or alternative steps may be implemented.Further, one or more of the recited steps may be omitted in exemplaryaspects. Further, it is contemplated that any combination ofcomponents/tools and steps may be implemented.

FIG. 7 depicts a flow diagram 700 representing a method of cleaning anelastomeric component with plasma, in accordance with aspects hereof. Ata block 702, an image of the component is captured. The image may beused to identify a particular component and to generate an appropriatetool path for a plasma source to traverse when applying plasma. Theimage may be provided to a computing device that is responsible forexecuting instructions for processing the image to identify thecomponent and/or develop an appropriate tool path. As depicted in block704, a tool path is generated. The tool path may be generated by thecomputing device taking into consideration constraints provided (e.g.,general tool path) in combination with component specific informationderived from the captured image (e.g., orientation, location, tolerancevariations, and the like). As previously discussed, the tool path mayinclude height offsets that are effective for maintaining a desireddistance between the plasma source and the surface of the component.

Based on the tool path, a computing device in connection with amulti-axis mechanism may be implemented to position the plasma torchrelative to the component, such as at an initial point in space for thetool path, as indicated at a block 706. The position may include X, Y,and Z coordinates along with rotational angles along any of the axis forappropriate application of plasma. At a block 708, plasma is applied tothe component while the plasma source is moved along the tool path.Movement of the plasma source instead of only moving the component mayallow for a more appropriately applied plasma with a faster throughput,in an exemplary aspect. At a block 710, carbonyl functional groups areformed in an altered region of the component to enhance adhesioncharacteristics of the component and to eliminate, in an exemplaryaspect, chemical cleaning and priming. Further, at a block 712, C—Cbonds and C—H bonds in the altered region are reduced, to furtherenhance the adhesion characteristics of the component. To limit thermalinput and reduce thermal stress on the component, multiple plasmaapplications may be implemented to achieve a desired level of surfacepreparation on the component. If additional applications of plasma areto be provided, a decision block 714 returns to the block 706. Uponreturning to block 706, it is contemplated that a different plasmasource may be implemented or the same plasma source may be used again,in exemplary aspects.

If additional applications of plasma are not to be applied at decisionblock 714, the method advances to a block 716 at which an adhesive isapplied to the component. The adhesive may be applied to the entirety ofthe plasma cleaned surface or it may be selectively applied. Further, itis contemplated that the adhesive may be applied at the control of acomputing device and/or a multi-axis mechanism, in an exemplary aspect.At a block 718, the component is mated with a second component. Themating of the components is the combining of the components with theadhesive adhering the two components. The mating may be done manually orin an automated manner. In an example, the mating is the alignment andjoining of a midsole portion with an outsole portion to form a shoebottom unit.

While specific steps are depicted in an exemplary order with FIG. 7, itis understood that additional or alternative steps may be implemented.Further, one or more of the recited steps may be omitted in exemplaryaspects.

From the foregoing, it will be seen that this invention is one welladapted to attain all the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

While specific elements and steps are discussed in connection to oneanother, it is understood that any element and/or steps provided hereinis contemplated as being combinable with any other elements and/or stepsregardless of explicit provision of the same while still being withinthe scope provided herein. Since many possible embodiments may be madeof the disclosure without departing from the scope thereof, it is to beunderstood that all matter herein set forth or shown in the accompanyingdrawings is to be interpreted as illustrative and not in a limitingsense.

The invention claimed is:
 1. A plasma treatment system, the plasmatreatment system comprising: a first plasma torch; a first multi-axisconveyance mechanism coupled with the first plasma torch, the firstmulti-axis conveyance mechanism able to position the first plasma torchwithin a 20-40 millimeter offset height range from a surface of anelastomeric component; a component identification mechanism; andcomputer readable media having instructions embodied thereon that whenexecuted by a processor: generate a tool path for the first multi-axisconveyance mechanism based on an input from the component identificationmechanism; and control the first plasma torch and the first multi-axisconveyance mechanism to apply plasma to the surface while maintainingthe 20-40 millimeter offset height range to form an altered regionextending from the surface into the elastomeric component.
 2. The plasmatreatment system of claim 1, wherein the component identificationmechanism comprises a vision system adapted to capture one or moreimages of the elastomeric component.
 3. The plasma treatment system ofclaim 1, further comprising a second plasma torch coupled with a secondmulti-axis conveyance mechanism, the computer readable media furtherhaving instructions to control the second plasma torch and the secondmulti-axis conveyance system in connection with the first plasma torchand the first multi-axis conveyance mechanism.
 4. The plasma treatmentsystem of claim 1, further comprising an adhesive applicator, and thecomputer readable media further having instructions to control theadhesive applicator to apply adhesive to the surface of the elastomericcomponent.
 5. The plasma treatment system of claim 4, wherein theadhesive applicator is coupled to a movement mechanism adapted to movethe adhesive applicator prior to or during application of the adhesiveto the surface of the elastomeric component.
 6. The plasma treatmentsystem of claim 1, wherein the elastomeric component is an elastomericfootwear component.
 7. The plasma treatment system of claim 1, furthercomprising a conveyance mechanism adapted to shift the elastomericcomponent from a first position that is adjacent the first plasma torchto a second position that is distal from the first plasma torch, and thecomputer readable media further having instructions to control theconveyance mechanism.
 8. The plasma treatment system of claim 1, whereinthe first plasma torch comprises a plasma generator adapted to utilize amulti-gas composition at atmospheric pressure to form the plasma.
 9. Theplasma treatment system of claim 8, wherein the tool path is amulti-pass tool path.
 10. The plasma treatment system of claim 1,wherein the tool path comprises a perimeter-based tool path.
 11. Theplasma treatment system of claim 1, wherein the tool path comprises amotion path that includes movement from a first side of the elastomericcomponent to a second opposing side of the elastomeric component. 12.The plasma treatment system of claim 1, wherein the first multi-axisconveyance mechanism is adapted to position the first plasma torchwithin a 35-40 millimeter offset height range from the surface of theelastomeric component.
 13. The plasma treatment system of claim 1,wherein the first plasma torch is adapted to form the altered regionextending into the elastomeric component from the surface to a depthgreater than 10 nanometers.
 14. The plasma treatment system of claim 13,wherein the first plasma torch is further adapted to form carbonylfunctional groups in the altered region extending into the elastomericcomponent from the surface to a depth greater than 10 nanometers, thecarbonyl functional groups resulting in a carbon atomic percentage of 2%to 15%.
 15. The plasma treatment system of claim 13, wherein the firstplasma torch is further adapted to reduce a carbon atomic percentage ofcarbon-to-carbon and carbon-to-hydrogen bonds in the altered region by arange of 28% to 17%.
 16. A plasma treatment system, the plasma treatmentsystem comprising: a first plasma torch, the first plasma torchcomprising a plasma generator adapted to utilize a multi-gas compositionat atmospheric pressure to form plasma; a first multi-axis conveyancemechanism coupled with the first plasma torch, the first multi-axisconveyance mechanism able to position the first plasma torch within a20-40 millimeter offset height range from a surface of a component; acomponent identification mechanism; and computer readable media havinginstructions embodied thereon that when executed by a processor:generate a multi-pass tool path based on input from the componentidentification mechanism; and control the first plasma torch and thefirst multi-axis conveyance mechanism to apply the plasma to the surfacewhile maintaining the 20-40 millimeter offset height range to form analtered region extending from the surface into the component.
 17. Theplasma treatment system of claim 16, wherein the componentidentification mechanism comprises a vision system adapted to captureone or more images of the component.
 18. The plasma treatment system ofclaim 16, further comprising a second plasma torch coupled with a secondmulti-axis conveyance mechanism.
 19. The plasma treatment system ofclaim 16, wherein the first plasma torch is adapted to form the alteredregion extending into the component from the surface to a depth greaterthan 10 nanometers.
 20. The plasma treatment system of claim 19, whereinthe first plasma torch is further adapted to form carbonyl functionalgroups in the altered region extending into the component from thesurface to a depth greater than 10 nanometers, the carbonyl functionalgroups resulting in a carbon atomic percentage of 2% to 15%.